* {
	margin: 0;
	padding: 0;
}

.plat {
	position: fixed;
	top: 50%;
	left: 50%;
	width: 380px;
	height: 190px;
	background-color: #f40;
	margin-left: -190px;
	margin-top: -90px;
}

.circle1,
.circle2,
.circle3,
.circle4,
.circle5 {
	position: absolute;
	width: 100px;
	height: 100px;
	border: 10px solid black;
	border-radius: 50%;
}

.circle1 {
	border-color: red;
	left: 0px;
	right: 0px;
}
.circle2 {
	border-color: green;
	left:130px;
	top: 0px;
	z-index: 3;
}
.circle3 {
	border-color: yellow;
	left: 260px;
	top: 0px;
	z-index: 5;
}
.circle4 {
	border-color: black;
	left: 65px;
	top: 70px;
}
.circle5 {
	border-color: blue;
	left: 195px;
	top: 70px;
	z-index: 4;
}